A compressor assembly including a motor for driving one or more compressor rotors.

Abstract

The compressor assembly (1) comprises a compressor assembly housing (27), a motor (2) driving one or more compressor rotors (11, 12), an oil reservoir (47), an oil cooler (48) and an oil filter (50), the motor (2) having a motor jacket (51) with a first group (117) of passages (52, 79) for cooling the motor (2), and the compressor assembly housing (27) with one or more through passages (67, 68, 123, 125, 126, 128, 129, ...) forms at least a part of the oil piping (90-101, 105-116, ...) interconnecting the components (2, 7, 9, 34, ...) of the compressor assembly (1).

Description

[Technical field]

[0001] The present invention relates to a compressor assembly that includes a compressor assembly housing and a motor that drives one or more compressor rotors of a compressor element.

[0002] The compressor assembly also includes an oil circulation system for cooling and lubricating the components of the compressor assembly, the oil circulation system including an oil reservoir from which oil is circulated through oil piping in the oil circulation system to the associated components to be lubricated or cooled and back to the oil reservoir.

[0003] Additionally, the oil circulation system further comprises an oil cooler for cooling the oil circulating through the oil circulation system, and an oil filter for filtering the oil flowing through one or more lines of the oil circulation system.

[0004] The oil piping is intended to connect the components of the compressor assembly together. These compressor assembly components may be the main components such as the motor or compressor rotor, the motor shaft bearings, the gears, etc., but they may also be components of the oil circulation system, such as the oil reservoir, the oil filter, the oil cooler, etc. In other words, these components of the oil circulation system are also considered as being part of the compressor assembly.

[0005] The present invention is specifically interested in compressor assemblies that are oil-free or oil-less compressor elements, meaning that no oil for lubrication is injected between the compressor rotors themselves of the compressor elements, but other components such as bearings and gears are normally lubricated by oil in an oil circulation system. The reason for using oil-free or oil-less compressor elements is that the fluid that is pressurized or compressed in the compressor elements is kept free of oil or is not contaminated by oil, which is very important, for example, in food processing applications.

[0006] Nevertheless, the present invention is not limited to compressor assemblies with oil-free or oil-less compressor elements, for example compressor assemblies with oil injected compressor elements are not excluded from the present invention.

[0007] Different techniques may be used to compress or pressurize the fluid in the compressor element. The present invention relates to a compressor assembly in which the compressor element is a rotary compressor element having a compressor rotor driven by a motor for rotational movement.

[0008] The motor is typically an electric motor, but may also be a combustion engine, or in principle any other kind of rotary driver or actuator, or combination of devices for generating rotary movement.

[0009] The motor of the compressor assembly according to the invention has a motor housing with a central motor housing body implemented as a jacket, the jacket being provided with passages connected to the oil piping of an oil circulation system for circulating oil through the motor jacket.

[0010] Typically, the motor housing is interconnected with a compressor housing of the compressor element to form a compressor assembly housing of the compressor assembly.

[0011] In a possible embodiment, the motor housing consists entirely of the motor jacket alone, which is directly connected to an interconnecting flange for connecting the motor housing to the compressor housing. In another embodiment, typically when the motor is pre-assembled before connecting it to the compressor element of the compressor assembly, the motor housing can be executed with a flange or cover provided on one or both opposite sides of the central motor housing body forming the motor jacket.

[0012] The motor essentially has a motor shaft that extends through the motor housing and possibly through part of the compressor housing, the motor shaft having a drive side whereby the motor shaft is connected or coupled to an associated compressor rotor shaft or other part of the compressor element.

[0013] This can be achieved in a direct manner by directly interconnecting or coupling the shaft of the associated compressor rotor to the motor shaft by means of a direct coupling, which can be contained in a part of the motor housing or in a part of the compressor housing, but also in an intermediate housing part provided between the motor housing and the compressor housing, or in an intermediate chamber of the compressor assembly housing.

[0014] In other embodiments, the coupling or interconnection between the motor shaft and the associated compressor rotor shaft is achieved in an indirect manner using an intermediate gear transmission or gear box, which is typically housed in an intermediate gear transmission housing that is positioned between the compressor housing and the motor housing.

[0015] The compressor elements of the compressor assembly are intended to compress or pressurize a fluid, typically a gaseous fluid, such as air or other gases such as oxygen, carbon dioxide, nitrogen, argon, helium, or hydrogen, etc. However, it is not excluded from the invention that the compressor elements be used to compress or pressurize denser fluids, such as water vapor. [Background technology]

[0016] Compressor assemblies are known from the state of the art that comprise an oil-free, or oil-less, or oil-injected compressor element that is directly coupled to a motor or indirectly coupled by means of a gear transmission that is coupled to the motor.

[0017] Regardless of whether the compressor elements are oil-free, oil-less, or oil-injected compressor elements, many elements or components of such compressor assemblies need to be lubricated or cooled by oil, and for that reason the compressor assemblies are provided with an oil circulation system.

[0018] Compressor assembly elements or components that require lubrication or cooling by oil typically include gears such as timing gears or timing gears of the gear transmission between the compressor elements and the compressor assembly motor, the compressor outlet, compressor rotor shaft bearings, motor shaft bearings, etc.

[0019] The oil drive means for circulating oil through the oil circulation system may consist of the compressor rotor of the compressor assembly itself, or the compressor rotor of another oil drive means, or a combination.

[0020] To cool the motor of the compressor assembly, the motor housing is executed as a jacket provided with passages through which the oil of the oil circulation system can flow.

[0021] An oil reservoir or sump, an oil pump, an oil cooler, and an oil filter are also typically included in the oil circulation system.

[0022] Much oil inlet and outlet piping is required to circulate oil from the oil reservoir, to the motor housing jacket, to the components or elements of the compressor assembly to be lubricated or cooled, and back to the oil reservoir. These piping also interconnect the oil drive, oil cooler, and oil filter with each other and with the elements and components of the compressor assembly.

[0023] It can be easily seen that the number of oil pipes and components involved makes a successful compact and efficient design somewhat complicated.

[0024] Furthermore, wherever oil piping must be connected to one of the aforementioned elements or components of the compressor assembly or oil circulation system, there is a need for suitable sealing.

[0025] The more components and piping involved, the greater the risk of an oil leak at one location or another, which is a major danger to the proper functioning of the compressor assembly and to the proper lubrication and / or cooling of the compressor assembly's vital elements, so this situation should also be avoided as much as possible.

[0026] Therefore, a major challenge in designing a suitable compressor assembly of the type concerned is to arrange all the necessary oil circuit components (e.g., oil pumps, piping, cooling passages, injection passages, oil filters, breathers, and other elements) in a compact manner to reduce the required number of components and the space and footprint of the compressor assembly.

[0027] Another challenge is to minimize the number of connections between the oil piping and the components of the compressor assembly and to reduce the risk of oil leaks.

[0028] Moreover, in practice, compressor assemblies are required in different sizes corresponding to different required compression outputs which depend on the required outlet pressure of the compressed fluid and / or the flow rate of the compressed fluid at the outlet of the compressor elements of the compressor assembly, which means that the compressor assembly housings must also be made in different sizes.

[0029] Such housings for the motor or compressor elements of the compressor assemblies are often made in a casting process. For casting, a mold is required and each different design is made for each other mold. Since making the molds is labor intensive and somewhat expensive, it is only cost effective to make a series of a particular type or size of compressor assemblies if the total quantity to be made is large enough. Therefore, according to the state of the art, there is no great flexibility to change the design or size of the compressor assemblies.

[0030] Furthermore, in applications where the compressor assembly involved comprises compressor elements that are oil-free or oil-less compressor elements, specific problems must be solved.

[0031] Indeed, in oil-injected compressor elements, the oil is circulated in an oil circulation system by means of a pumping force generated by the compressor rotors of the compressor elements themselves, this being possible because the oil is injected between their compressor rotors.

[0032] However, in oil-free or oil-less compressor elements this is not possible since contamination of the pressurized fluid by the lubricating oil is simply not acceptable in such oil-free or oil-less compressor elements.

[0033] As a result, the role of generating pumping force for pumping oil in the oil circulation system cannot be performed by the compressor rotor, and an additional oil driving means or oil driving means with increased capacity for generating pumping force, such as an oil pump, located outside the compression chamber, must be provided for that purpose.

[0034] This means that in applications where the compressor assembly comprises oil-free or oil-less compressor elements, the need for integration of additional oil pumps or other oil driving means and / or additional oil piping into the compressor assembly design is generally higher than in oil-injected compressor applications. The problems in designing a compact, efficient and well-integrated version of such compressor assemblies with oil-free or oil-less compressor elements are relatively more complex for the same reasons.

[0035] Also, oil-free or oil-less compressor elements require the need for additional oil pumps or oil drive means, or the need to increase the capacity of such oil pumps or oil drive means to pump oil through the oil circulation system of the compressor assembly, which implies additional costs due to additional components and / or increased energy consumption.

[0036] Another important aspect of the present invention is that in oil-injected compressor elements, all lubricating and cooling oil is usually circulated under pressure provided by the compressor rotor. The requirements for the quality of this lubricating and cooling oil are high, since the entire flow of oil penetrates the compressor chamber between the compressor rotors. For reliable functionality of the compressor elements, it is important that this lubricating and cooling oil is free of contamination, which is obtained by passing the oil through an oil filter. Therefore, the filter requirements in oil-injected compressor elements are very high.

[0037] On the other hand, in oil-free or oil-less compressor elements, oil is not injected between the compressor rotors, and therefore the requirements for filtering the lubricating and / or cooling oil are different than in oil-injected compressor elements.

[0038] Clearly, when designing a compressor assembly, many different aspects must be considered, such as the number of components, the number of devices, the number of oil piping connections between these components and devices integrated into the compressor assembly, the cost and complexity of manufacture, the quality and purity of the lubricating and / or cooling oil in certain parts of the assembly, the size and power of the assembly, etc. Thus, designing such a compressor assembly in a compact, cost-effective and reliable manner involves many techniques and is far from clear. Summary of the Invention [Problem to be solved by the invention]

[0039] It is an object of the present invention to overcome one or more of the problems set forth above, and / or possibly still other problems.

[0040] Specifically, it is a goal of the present invention to provide a more integrated compressor assembly design in which the number of oil piping connections, the need to seal those connections, are substantially reduced, thereby reducing the risk of compressor assembly failure or performance degradation caused by leaking lubricating or cooling oil or by contamination of that oil.

[0041] Another object of the present invention is to reduce the vulnerability of connections between oil piping and components of a compressor assembly.

[0042] Another object of the present invention is to provide a solution that is cost-effective and does not require costly changes to the manufacturing process of the compressor assembly, allowing a relatively easy adaptation of the compressor assembly design, especially as far as the length of the compressor assembly is concerned.

[0043] Yet another object of the present invention is to provide a compressor assembly with an optimized or improved oil filtration system in which lubricating and / or cooling oil is filtered in a manner adapted to the needs of the associated components of the compressor assembly.

[0044] It is a further object of the present invention to achieve one or more of the foregoing objects in a compressor assembly including a compressor element that is an oil-free or oil-less rotor compressor element.

[0045] Finally, it is also an object of the present invention to develop a compact compressor assembly in which the motor shaft is coupled to the compressor rotor shaft directly or, preferably, indirectly through a gear transmission of limited size, and in which the motor, compressor elements and possibly the gear transmission are integrated in the compressor assembly housing. [Means for solving the problem]

[0046] To that end, the present invention relates to a compressor assembly comprising a compressor assembly housing and a motor driving one or more compressor rotors of a compressor element, and an oil circulation system for cooling and lubricating the components of the compressor assembly, the oil circulation system comprising an oil reservoir and an oil cooler and an oil filter for cooling and filtering, respectively, the oil flowing through one or more oil pipes of the oil circulation system interconnecting the components of the compressor assembly, the motor having a motor housing with a central motor housing body implemented as a motor jacket in which motor jacket passages are provided for circulating oil through the motor jacket, the motor jacket comprising at least a first group of motor jacket passages consisting of one or more such passages intended to cool the motor, the compressor assembly housing comprising one or more through passages for guiding oil through the compressor assembly housing, such through passages forming at least a part of the aforementioned oil pipes interconnecting the components of the compressor assembly.

[0047] A first important aspect of such a compressor assembly according to the invention is that the motor jacket of the compressor assembly comprises a first group of motor jacket passages consisting of one or more such passages intended to cool the motor, whereby the motor jacket at least partially forms a kind of heat exchanger for cooling the motor mounted in the motor housing. With this first group of motor jacket passages, the cooling of the motor is to a large extent integrated into the compressor assembly housing.

[0048] Another important aspect of the compressor assembly according to the present invention is that the compressor assembly housing includes one or more through passages for directing oil through the compressor assembly housing, in which case the oil piping or piping interconnecting the components of the compressor assembly is at least partially integrated in the compressor assembly housing.

[0049] A significant advantage of such a design of the compressor assembly according to the present invention is that the compressor assembly has fewer or weaker connections between its oil piping and components, thereby substantially reducing the risk of oil leaks.

[0050] Another advantage of such a compressor assembly according to the invention is that it is substantially more compact than existing compressor assemblies of the same type.

[0051] Yet another advantage of the compressor assembly according to the present invention is that it can be assembled in a relatively easy manner since it requires less work from the mechanic or engineer involved to connect and seal the oil piping to its components.

[0052] In a preferred embodiment of a compressor assembly according to the invention, the compressor assembly housing accommodates an integrated compressor assembly component comprising at least a motor, a compressor element and interconnection means for interconnecting the motor and the compressor element, and possibly one or more other integrated compressor assembly components such as an oil reservoir, an oil filter, an oil cooler, an oil pump, and possibly still other integrated compressor assembly components, and the integrated compressor assembly component, or an integrated element of such integrated compressor assembly component which needs to be lubricated or cooled, is connected to other such integrated compressor assembly components or to other such integrated elements by means of the aforementioned oil piping which is generally formed by through passages provided in the compressor assembly housing to form the generally integrated oil piping.

[0053] A major advantage of such an embodiment of the compressor assembly according to the invention is that the oil piping or piping interconnecting the compressor assembly components integrated in the compressor assembly housing is entirely integrated in the compressor assembly housing, meaning that such an oil piping connection between two integrated compressor assembly components is entirely formed by a through passage in the compressor assembly housing.

[0054] In this way, the number of oil pipes mounted outside the compressor assembly housing is substantially reduced. As a result, the risk of oil leakage and rupture of the oil pipes is also significantly reduced. Therefore, the design is more robust and reliable during operation.

[0055] In an even more preferred embodiment of the compressor assembly according to the invention, the respective interconnecting oil piping between the integrated compressor assembly components and / or the integrated elements thereof is formed by the generally integrated oil piping as described above.

[0056] Such an embodiment of the compressor assembly according to the invention is highly advantageous since all oil piping between integrated compressor assembly components or elements thereof is realized by an entirely integrated oil piping, formed by through passages extending entirely through the compressor assembly housing between the relevant integrated components or elements.

[0057] This means that a somewhat more sophisticated integration of the oil piping in the compressor assembly has been carried out, resulting in greater reliability during operation, compactness of the design, increased efficiency during assembly, and reduced costs of manufacture.

[0058] The compressor assembly according to the present invention preferably also comprises one or more oil cooling piping sections extending from the oil cooler to the oil reservoir in such a manner that the first group of motor jacket passages are each included in one of the one or more oil cooling piping sections for cooling the motor.

[0059] It will be appreciated that by including a first group of motor jacket passages in the oil cooling piping section extending from the oil cooler to the oil reservoir, the necessary cooled oil is provided to the motor for cooling the motor. Oil accumulated during the passage of heat from the motor through the motor jacket passages is returned to the reservoir from where it is pushed again through the oil circulation system for cooling in the oil cooler at a later stage.

[0060] In yet another preferred embodiment of the compressor assembly according to the invention, the oil circulation system of the compressor assembly comprises at least a first circulation loop and a second circulation loop, in which oil circulates between an oil reservoir and an oil cooler and back, the first circulation loop being a non-filtered circulation loop in which no oil filter is included and the second circulation loop being a filtered circulation loop in which an oil filter is provided for filtering the oil, and the first group of motor jacket passages are included in the first non-filtered circulation loop, and the motor jacket passages form cooling passages for cooling the motor housing jacket.

[0061] In such an embodiment of the compressor assembly according to the invention, not all of the oil circulating through the oil circulation system needs to be filtered all the time, instead the total flow of oil in the oil circulation system is split into two flows of oil flowing through two different circulation loops, a filtered circulation loop and a non-filtered circulation loop.

[0062] Importantly, the oil flow through the motor jacket for cooling the oil is part of an unfiltered circulation loop and is generally somewhat greater than the filtered oil flow for lubricating the bearings and gears of the compressor assembly.

[0063] This is a very advantageous arrangement. Indeed, the service life of a filter is determined by a) the oil contamination and b) the flow rate passing through the filter. In the embodiment of the compressor assembly as considered herein, most of the oil flow rate is used for cooling without being filtered. Therefore, the service life of the filter in the oil circulation system is extended to a great extent by only filtering the more limited oil flow of oil used for lubrication.

[0064] This requires some explanation. Filtering all the oil in the oil circulation system, and by extension using the filtered oil as a cooling medium as well, has some advantages in some respects, since it may allow for a somewhat less complicated mechanical design. Indeed, the motor bearings may then be lubricated with filtered oil provided through a lubrication point that may be formed, for example, by a simple bleed-off point that draws the filtered oil from a passage in the motor jacket. Such a simple design for bringing filtered oil to the motor bearings is not possible when the passages in the motor jacket carry unfiltered cooling oil.

[0065] However, the drawback of filtering all the oil in an oil circulation system is that the system needs to be maintained more frequently, or alternatively, an oversized oil filter should be used. Also, the pressure drop across the oil filter increases quadratically with the flow rate going through the oil filter. Therefore, to reduce this pressure drop, the size of the filter must be large enough to keep the flow rate through the filter low enough. This is a problem if the filtered oil serves not only lubrication purposes but also cooling purposes.

[0066] The feature of the present invention of splitting the total oil flow into a filtered circulation loop for lubrication and an unfiltered circulation loop for cooling is a clever way of designing a compressor assembly. The drawback of making the design slightly more complex, insofar as supplying filtered lubricating oil to several parts of the assembly is concerned, is largely offset by the advantage that a smaller oil filter can be used, the oil filter has a longer service life and needs to be maintained less frequently. By intelligently integrating the filtered and unfiltered oil piping in the motor jacket, such a design according to the present invention is also very compact, reliable and robust.

[0067] In another preferred embodiment of the compressor assembly according to the invention, the motor jacket comprises, instead of the first group of motor jacket passages, a second group of motor jacket passages consisting of one or more such passages each forming the aforementioned through passage or a part of such a through passage for guiding oil through the motor jacket.

[0068] A great advantage of such an embodiment of the compressor assembly of the invention is that one or more oil lines not intended to cool the motor are also partially integrated in the motor jacket, which in this case comprises not only a first group of motor jacket passages intended to cool the motor, but also a second group of motor jacket passages not intended to cool and which guide oil through the motor jacket, for example towards an oil cooler or towards an oil reservoir or coming from an oil pump or coming from an oil reservoir. This second group of motor jacket passages is a very efficient means for realizing a compressor assembly in which many components and elements and the interconnecting oil lines between them are integrated in the compressor assembly housing. In this way, a very compact and reliable design can be realized which is much easier to assemble than known compressor assemblies.

[0069] The choice of at least partially integrated oil piping between the components and elements of the compressor assembly in the motor jacket not intended for motor cooling together with other motor jacket passages of a first group intended for motor cooling is not obvious. A careful balance needs to be achieved between the reduction of motor cooling on the one hand and the increased integration of the components in the compressor assembly housing on the other hand.

[0070] In a possible embodiment of the compressor assembly according to the invention, the following oil piping of the compressor assembly: - oil piping for supplying oil from the oil reservoir to an oil filter and / or oil cooler; - an oil line connected to the outlet of the oil filter for supplying filtered oil to the components of the compressor assembly; - an oil pipe connected to the outlet of the oil cooler for supplying cooled oil to the components of the compressor assembly; - oil injection piping for supplying oil to the components of the compressor assembly for lubrication purposes; and / or - an oil discharge pipe for discharging oil coming from the compressor assembly components towards the oil reservoir; are at least partially integrated in the motor jacket by being partially formed by one or more motor jacket passages of the second group.

[0071] Depending on the application and needs, more or less of these oil lines may be integrated either partially or fully in the compressor assembly housing and in the motor jacket.

[0072] In a preferred embodiment of the compressor assembly according to the invention, the oil circulation system comprises an oil pump for providing a driving force for circulating oil from the oil reservoir, through the oil piping of the oil circulation system, to the relevant components to be cooled and / or lubricated and back to the oil reservoir.

[0073] In that case, preferably the following oil piping of the compressor assembly: - an oil pump suction line for connecting the oil reservoir with an inlet of an oil pump of the compressor assembly; and / or - Oil pump pressure piping to connect the oil pump outlet to an oil cooler and / or oil filter one or more of are at least partially integrated into the motor jacket by being partially formed by one or more motor jacket passages of the second group of motor jackets, or are at least partially integrated into the compressor assembly housing.

[0074] A first important aspect of such a compressor assembly according to the invention is that an oil pump is provided for circulating oil through the oil piping of the oil circulation system of the assembly.

[0075] A major advantage of this embodiment is that the oil pump provides at least a portion of the necessary driving force for the circulation of oil through the oil circulation system, as a result of which the oil is not necessarily pumped by the driving force provided by the compressor rotor of the compressor assembly, so that the compressor assembly is suitable for oil-injected as well as oil-free types of compressors.

[0076] Therefore, the aforementioned preferred properties of the compressor assembly according to the present invention are particularly advantageous for application in embodiments in which the compressor elements of the compressor assembly are oil-free or oil-less compressor elements.

[0077] Indeed, in an oil-free or oil-less compressor assembly, there is always a need for an oil pump to generate the driving force to pump the lubricating or cooling oil through the oil circulation system.

[0078] In a preferred embodiment of the compressor assembly according to the invention, the oil pump is integrated into the motor housing or is mounted on the motor housing cover or other part of the compressor assembly housing provided on the non-drive or drive side of the central motor housing body and is driven by the motor shaft of the motor.

[0079] The non-drive side is opposite the drive side of the central motor housing body, and the drive side is the side of the central motor housing body on which the motor drives the compressor rotor of the compressor element.

[0080] A significant advantage of such an embodiment of the compressor assembly of the present invention is that it allows for a very compact compressor assembly of limited size, where the many elements of the compressor are integrated in an efficient and logical manner.

[0081] In fact, the oil pump is so close to the motor and its motor shaft that it can be driven by said motor shaft together with the compressor rotor of the compressor element, so that no additional drive means are required to drive the oil pump.

[0082] Another advantage of such an embodiment of the compressor assembly according to the invention, in which the oil pump is driven directly by the same motor of the compressor assembly that also drives the compressor elements, and not by additional external drive means, is that it is more efficient and more reliable to include the oil pump as a mechanical part directly coupled to the main motor. In this way, at least in the absence of mechanical failures or obstructions in the oil circuit, lubrication of the bearings is always guaranteed when the motor is running. An external oil pump driven electrically is less reliable, since a simple communication failure may prevent the pump from running when the machine is started. Too long a "running out of oil" without lubrication would result in harmful damage to the motor and / or the bearings of the compressor elements or intermediate gears.

[0083] In a preferred embodiment of the compressor assembly according to the invention, the oil pump is furthermore connected at its outlet directly to the aforementioned motor jacket passage in the central motor housing body.

[0084] A major advantage of such an embodiment of the compressor assembly of the present invention is that the oil pressure piping of the oil pump is also integrated into the motor housing, so that no additional external oil piping needs to be connected to the oil pump outlet. This also allows for a very robust design, substantially reducing the risk of oil leakage at the oil pump outlet. Moreover, with such a design, failure of the external oil piping at the oil pump outlet, e.g. caused by accidental destruction or material fatigue, is not possible, so the reliability of the compressor assembly is increased.

[0085] In a possible embodiment of the compressor assembly according to the invention, the motor housing is provided with a through passage passing through the central motor housing body and through a motor housing cover provided at the opposite end of the central motor housing body, the outlet of the oil pump being directly connected to this through passage and at least partially forming the oil pump pressure piping of the oil pump.

[0086] Such a combination of an integrated oil pump and oil pump pressure piping partially integrated in the motor housing ensures compactness and reliability during operation.

[0087] In yet another preferred embodiment of the compressor assembly according to the invention, the motor housing additionally comprises, at the drive side of the central motor housing body, a drive side motor housing cover or cap adjacent the compressor rotor driven by the motor, and at the non-drive side of the central motor housing body, a non-drive side motor housing cover or cap on the opposite side of the central motor housing body, the motor housing cover or cap comprising one or more interconnecting passages cooperating in assembly with the first group of motor jacket cooling passages to interconnect the associated cooling passages to form single or multiple configured cooling passages for cooling the motor housing jacket.

[0088] The advantage of such an embodiment of the compressor assembly according to the invention is that several motor jacket passages can be merged into a configured cooling passage by means of interconnecting passages in the cover or cap of the central motor housing body, so that a configured cooling passage is formed with a length that is several times the length of a single motor jacket passage. Different configurations can be easily achieved by using a cap or cover with an interconnecting passage that changes the configuration. Furthermore, the cap or cover allows a reduction in the connection between the oil cooler and the motor jacket passage, since not every single motor jacket passage needs a connection to the oil cooler. It is sufficient to connect the configured cooling passage to the oil cooler.

[0089] In a preferred embodiment of the compressor assembly according to the invention, the passages in the motor jacket extend in an axial direction parallel to the axial direction of the motor shaft of the motor.

[0090] This means that the central motor housing body can be made with a cross-sectional area perpendicular to the motor shaft that is constant or unchanging when considered in said axial direction, i.e. in the direction of the length of the motor or part thereof.

[0091] So, the advantage of such a compressor assembly according to the invention is that the same manufacturing method can be used to make different lengths of central motor housing bodies for the motors of the compressor assembly, so that compressor assemblies of different lengths can be easily made. Obviously, in the housing of the compressor assembly with increased length, devices with increased drive power, or compression power, or compression pressure, or flow rate can be installed.

[0092] This is advantageous in that different compressor assemblies can be made, even in not too large quantities, with somewhat different characteristics, without substantially increasing the cost and / or complexity of manufacture.

[0093] Another advantage of such a compressor assembly according to the invention, in which the passages in the motor jacket extend in an axial direction parallel to the axial direction of the motor shaft, is that oil can be conveyed through the motor jacket from one side to the opposite side. Such an arrangement is very efficient in conveying oil through the motor jacket, providing easy flow of oil, thereby providing high cooling or oil transport capacity.

[0094] These axially oriented passages can also be easily combined or connected to one another in caps, flanges, or covers on opposite sides of the motor jacket, so that different configurations for directing other substances such as oil or water through the motor jacket can be easily constructed even with only a single type of motor jacket by simply using caps or covers with different internal passages.

[0095] Furthermore, oil-injected compressor elements are used in large scale and large volume and they have large differences in the size of the drive motor frame, while oil-free or oil-less compressor assemblies are used less frequently, made in smaller quantities and have smaller differences in size or capacity, so the production of different types of oil-free or oil-less compressor assemblies is usually hardly feasible from a cost perspective because the quantities made are too small.

[0096] An additional advantage of the provided solution with axially aligned passages in the central motor housing body is that it allows the production of motor housings with different lengths in the same or almost the same manufacturing process, which paves the way for the production of various types of compressor assemblies with oil-free or oil-less compressor elements at acceptable costs, even if only small batches of each type need to be produced.

[0097] Therefore, in a preferred embodiment of the compressor assembly according to the present invention, the central motor housing body is manufactured by extrusion.

[0098] The extrusion process is naturally well suited to producing objects with cross-sections that are constant or nearly constant in the axial direction.

[0099] Extrusion processes are also of great interest when objects with similar cross sections or profiles but different lengths must be produced, in which case changes to the design would require different molds, which is not entirely the case when casting processes are used.

[0100] In fact, the same extrusion die can be used to manufacture parts with the same extrusion profile for various lengths. On the other hand, compared to the casting process, the extrusion technique requires a higher initial investment.

[0101] Nevertheless, the disadvantage of a higher initial investment can be offset by the advantage that the same extrusion technique can be used for different types of housings without additional investment, which is not the case when casting technique is applied, since the same extrusion die can be used for motor housings of different lengths, so the overall amount of (different types of) products made can be large enough to justify the initial high investment.

[0102] Furthermore, the technology is more practical to make motor housings of different lengths, so the overall benefits of extrusion largely offset the initial high investment burden. This is particularly interesting for making compressor assemblies with oil-free compressor elements, as the oil-free market is shifting so that only smaller batches of each type of compressor assembly are required.

[0103] The invention will be further illustrated with reference to the drawings. [Brief description of the drawings]

[0104] [Figure 1] 1 is a schematic diagram in cross section of a portion of a first embodiment of a compressor assembly according to the present invention; [Diagram 2] FIG. 4 is a similar schematic cross-sectional view of a portion of a second embodiment of a compressor assembly according to the present invention. [Diagram 3] FIG. 1 is a schematic diagram of a complete compressor assembly according to the present invention, comprising oil-free compressor elements with pre-cooled oil injection. [Figure 4] FIG. 3 is a schematic diagram similar to that of FIG. 2 of a complete compressor assembly according to the invention, comprising oil-free compressor elements with uncooled oil injection. [Diagram 5] FIG. 2 is a perspective view of an unfinished central motor housing body of a compressor assembly according to the present invention; [Figure 6] FIG. 6 is a perspective view of the completed central motor housing body depicted in FIG. 5. [Figure 7] FIG. 7 is a perspective view of the completed central motor housing body of FIG. 6 after the stator has been inserted. [Figure 8] FIG. 7 is a front view of the completed central motor housing body, as indicated by arrow F08 in FIG. 6, showing the motor shaft bearing and oil injection into the motor shaft bearing. [Figure 9] FIG. 7 is a perspective view of the completed central motor housing body similar to that of FIG. 6, with the direction of oil flow in the first configuration indicated with arrows. [Figure 10] FIG. 10 is a front view taken along arrow F10 in FIG. 9 showing the same oil flow in a first configuration through the passages in the completed central motor housing body. [Figure 11] FIG. 10 is a perspective view of the completed central motor housing body similar to that of FIG. 9, with the direction of oil flow in the second configuration indicated with arrows. [Figure 12] FIG. 12 is a front view taken along arrow F12 in FIG. 11 showing the same oil flow in a second configuration through the passages in the completed central motor housing body. [Figure 13] FIG. 2 is a partially exploded view in perspective depiction of a more realistic compressor assembly according to the present invention. [Figure 14] FIG. 2 is a schematic diagram of a compressor assembly of the type depicted in FIG. 1 with indication of the main oil flows between the components of the compressor assembly and without the integration of oil piping in the compressor assembly housing away from the motor jacket cooling passages. [Figure 15]FIG. 15 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. [Figure 16] FIG. 15 is a schematic diagram similar to the representation of FIG. 14 of a compressor assembly in which an oil drain pipe is integrated in the motor jacket to drain oil coming from the motor bearings. [Figure 17] FIG. 17 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. [Figure 18] FIG. 17 is a schematic diagram of a compressor assembly similar to that depicted in FIG. 16, in which additional oil injection piping is integrated into the motor jacket for injecting oil towards the motor bearings, a configuration corresponding to the embodiment depicted in FIG. [Figure 19] FIG. 19 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. [Figure 20] FIG. 19 is a schematic diagram of a compressor assembly similar to that depicted in FIG. 18, in which the oil pump pressure piping is additionally partially integrated into the motor jacket and compressor assembly housing, as well as into an oil filter and oil piping connected to the oil filter. [Figure 21] FIG. 21 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. [Figure 22] FIG. 19 is an alternative view of the compressor assembly depicted in FIG. 18 in which the oil suction piping is integrated into the compressor assembly housing. [Figure 23] FIG. 23 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. [Figure 24] FIG. 21 is a diagram of a similar application of oil suction piping integrated in a compressor assembly housing of a compressor assembly similar to the compressor assembly as depicted in FIG. 20 . [Diagram 25] FIG. 25 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. 24. [Figure 26]FIG. 25 is a schematic diagram of a compressor assembly similar to that depicted in FIG. 24 in which the oil drain piping from the motor bearings is now integrated into the compressor assembly housing or sump, while additional oil drain piping is still provided in the motor jacket to drain leaking oil towards the oil reservoir. [Figure 27] FIG. 27 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. 26. [Figure 28] FIG. 27 is a schematic diagram of a compressor assembly similar to that depicted in FIG. 26, in which an oil filter and oil piping connected to the oil filter are also integrated into the compressor assembly housing. [Figure 29] FIG. 29 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. 28. [Diagram 30] FIG. 29 is a schematic diagram of a compressor assembly similar to that depicted in FIG. 28, where no additional oil drain piping is provided in the motor jacket to drain leaking oil towards an oil reservoir or sump. [Diagram 31] FIG. 31 is a cross-sectional view through the central motor housing body of the compressor assembly depicted in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0105] 1 shows a part of a first embodiment of a compressor assembly 1 according to the invention. The compressor assembly 1 comprises a motor 2, in this case an electric motor, mounted in a motor housing 3 and comprising a motor shaft 4 extending through the motor housing 3 in an axial direction XX'. The motor shaft 4 is provided with a motor rotor 5 which rotates together with the motor shaft 4 at a motor stator winding 6 which is fixedly mounted in the motor housing 3. The rotor shaft 4 is rotatably supported in the motor housing 3 by means of a motor shaft bearing 7. Alternatively, the use of a pair of motor shaft bearings for that purpose is not excluded from the invention.

[0106] At the drive side 8 of the motor 2 a compressor element 9 is coupled to the motor 2. As explained in the introduction, the present invention is of particular interest for compressor assemblies 1 in which the compressor element 9 is an oil-free or oil-less compressor element 9, although this is not necessarily the case.

[0107] Compressor element 9 is mounted in a compressor housing 10 and comprises compressor rotors 11 and 12 which cooperate with each other to compress a fluid 13 that is supplied to the compressor element 9 at a compressor inlet 14. Compressed or pressurized fluid 15 is discharged at a compressor outlet 16 to be supplied to a consumer or network of consumers of pressurized or compressed fluid 15.

[0108] The compressor rotors 11 and 12 each comprise a compressor rotor shaft, compressor rotor shaft 17 and compressor rotor shaft 18, respectively, on whose central part a rotor, compressor rotor 19 and compressor rotor 20, respectively, is provided. The compressor rotor 19 may be a female rotor 19 cooperating with a male rotor 20 forming the other compressor rotor 20, or vice versa. In practice, the compressor rotors 19 and 20, respectively, may be, for example, a screw rotor of a screw compressor element or a toothed rotor of a toothed compressor element, although other types are not excluded from the invention.

[0109] In a preferred embodiment of the compressor assembly according to the invention, the compressor element 9 of the compressor assembly 1 is an oil-free rotor compressor element 9 or an oil-free toothed compressor element 9, and the one or more compressor rotors 11 and / or 12 driven by the motor 2 are one or more compressor rotors or compressor teeth 19 and / or 20.

[0110] Compressor rotor shafts 17 and 18 are each rotatably supported in compressor housing 10 by compressor shaft bearing pairs, compressor shaft bearing pair 21 and 22 and compressor shaft bearing pair 23 and 24, respectively.

[0111] In order to drive the compressor element 9, or more precisely the compressor rotors 11 and 12 of the compressor element 9, by means of the electric motor 2, the motor shaft 4 is connected in a direct manner to the compressor rotor shaft 18 of the compressor rotor 12 by a direct connection 25 of the associated shafts 4 and 18. The connection 25 between the free end of the motor shaft 4 and the free end of the compressor rotor shaft 18 is located in an intermediate housing compartment 26 provided between the motor housing 3 and the compressor housing 10.

[0112] The motor housing 3 , the compressor housing 10 and the mid-housing compartment 26 together form a compressor assembly housing 27 .

[0113] In this case compressor rotor 12 is directly driven by motor shaft 4, while compressor rotor 11 is indirectly driven using interaction between coupling timing gears 28 and 29 mounted on the non-drive ends 30 of compressor rotor shaft 17 and compressor rotor shaft 18, respectively.

[0114] Finally, on the non-drive side 31 of the motor 2, i.e. opposite the drive side 8 where the motor 2 is coupled to the compressor element 9, the compressor assembly 1 is further provided with an oil pump 32. This oil pump 32 is integrated in the motor housing 3 or mounted on the motor housing 3 or on a motor housing cover of the motor housing 3.

[0115] This oil pump 32 is also driven directly by the motor shaft 4 of the electric motor 2 and is intended to provide the driving force for circulating oil in an oil circulation system 33 of the compressor assembly 1. This oil circulation system 33 is intended to provide oil to the components of the compressor assembly 1 for lubrication purposes or for cooling purposes or both.

[0116] Components of the compressor assembly 1 that typically require lubrication are, for example, bearings, such as motor shaft bearing 7 or compressor shaft bearings 21-24, or gears, such as timing gears 28 and 29. Components that require cooling are, for example, the electric motor 2, the compressed fluid 15 at the outlet 16 of the compressor element 9, the compressor element 9 itself, or other elements of the compressor assembly 1. An oil circulation system 33 is not depicted in Figure 1 but is discussed in more detail, for example, in connection with Figures 3 and 4.

[0117] FIG. 2 shows part of a second embodiment of a compressor assembly 1 according to the invention, which is very similar to the embodiment depicted in FIG.

[0118] A first difference with respect to the embodiment of Fig. 1 is that the motor shaft 4 is not here coupled to the compressor rotor shaft 18 by a direct coupling 25, as was the case in Fig. 1. In the embodiment of Fig. 2, the motor shaft 4 may be coupled or interconnected in an indirect manner to the compressor rotor shaft 18 of the compressor element 9 by means of an intermediate gear transmission 34 or gearbox. This intermediate gear transmission 34 or gearbox is housed in an intermediate gear transmission housing 35, which is positioned between the compressor housing 10 and the motor housing 3.

[0119] The intermediate gear transmission 34 in this case consists of a pair of intermeshing gears 36 and 37. Gear 36 is a driven pinion gear 36 fixedly mounted at a free end 38 of the compressor rotor shaft 18 which extends into the intermediate gear transmission housing 35.

[0120] The other gear 37 of the intermediate gear transmission 34, often referred to as the bull gear 37, is a drive gear 37 fixedly mounted on an additional gear transmission shaft 39 which is rotatably supported in the intermediate gear transmission housing 35 by means of a pair of bearings 40 and 41.

[0121] The additional gear transmission shaft 39 is directly connected to the motor shaft 4 by means of a direct connection 25 that connects a free end 42 of the additional gear transmission shaft 39 to a free end 43 of the motor shaft 4. Both associated shafts 4 and 39 extend into the intermediate housing compartment 26. In a possible embodiment, the direct connection 25 consists of a flexible coupling that can accommodate misalignment of the motor shaft 4 and the gear transmission shaft 39.

[0122] The intermediate housing compartment 26 is positioned between the intermediate gear transmission housing 35 and the motor housing 3, and the compressor housing 10, the intermediate gear transmission housing 35, the intermediate housing compartment 26, and the motor housing 3 together form the compressor assembly housing 27 in this example.

[0123] Another difference between the embodiment of Figure 2 and the embodiment of Figure 1 is the location of the oil pump 32. In the embodiment of Figure 2, the oil pump 32 is mounted directly on the free end 44 of the additional gear transmission shaft 39 opposite to the free end 42 of that shaft.

[0124] An additional gear transmission shaft 39 extends outwardly from the intermediate gear transmission housing 35 in the direction towards the compressor element 9. In the case of Fig. 2 the oil pump 32 can thus be said to be coupled to the electric motor 2 on its drive side 8, whereas in Fig. 1 this oil pump 32 was on the non-drive side 31. Naturally, it is not excluded from the invention to mount the oil pump 32 in a similar position on the non-drive side 31 of the motor housing 3, as was the case in the embodiment of Fig. 1.

[0125] Yet another difference from the embodiment of FIG. 1 is that in the embodiment of FIG. 2 the motor shaft 4 is not supported by a single bearing 7 but by a pair of motor shaft bearings 45 and 46 .

[0126] Figure 3 shows diagrammatically in its entirety a compressor assembly 1 according to the invention. The elements already described with reference to Figures 1 and 2 are repeated in this Figure 3 in a sort of exploded manner. Other elements of the compressor assembly 1 have been added, mainly showing details of an oil circulation system 33 for cooling and lubricating the components of the compressor assembly 1.

[0127] The oil circulation system 33 further includes an oil reservoir 47, an oil cooler 48 for cooling the oil 49 circulating through the oil circulation system 33, and an oil filter 50 for filtering the oil 49 flowing through the piping of the oil circulation system 33.

[0128] The oil circulation system 33 comprises oil piping interconnecting the components of the compressor assembly 1, such as the motor 2 and the oil cooler 48, or the oil filter 50 and the oil cooler 48. The oil circulation system 33 also comprises an oil pump 32 providing the necessary drive force to circulate oil 49 through the oil piping of the oil circulation system 33 from an oil reservoir 47 to the relevant components of the compressor assembly 1 to be cooled and / or lubricated and back to the oil reservoir 47. According to the invention, this oil pump 32 is preferably integrated in the motor housing 3 or mounted on a motor housing cover provided on the non-drive side 31 of the motor housing 3.

[0129] This is firstly advantageous because in this way the oil pump 32 can be driven by the same motor shaft 4 of the electric motor 2 which drives the compressor rotors 11 and 12 of the compressor element 9. This compact design has yet other advantages, as will become apparent later.

[0130] As shown, for example, in Figures 7 and 13, the motor housing 3 of the motor 2 comprises a central motor housing body 51 implemented as a jacket, which is provided with motor jacket passages 52 that are connected to oil piping of the oil circulation system 33 for circulating oil 49 through the motor jacket 51.

[0131] In a preferred embodiment of the compressor assembly 1 according to the invention, which is also the case in the depicted figures, these oil motor jacket passages 52 extend in axial directions AA', BB', CC', DD', EE', FF', ... parallel to the axial direction XX' of the motor shaft 4 of the motor 2, the motor jacket passages 52 extending throughout the central motor housing body 51 between the non-drive side 31 and the drive side 8 of the motor 2. This is for example clearly shown in figure 13.

[0132] Nevertheless, it is not excluded from the invention to provide the central motor housing body 51 with a motor jacket passage 52 that is configured in a completely different way, such as with parts extending circumferentially or parts that pivot around the axis of the motor housing.

[0133] In the embodiment detailed herein, the central motor housing body 51 is formed by an essentially cylindrical element 53, which can be considered as a double-walled element 53 with an outer wall 54 and an inner wall 55 connected to each other by means of a partition 56, which separates the different motor jacket passages 52 from each other. This is clearly shown, for example, in Fig. 7 and Fig. 8. In this case, there are eight such motor jacket passages 52, seven of which have a similar width and occupy the majority of the space between the inner wall 55 and the outer wall 54. The eighth motor jacket passage 52 at the bottom of the cylindrical element 53 has a substantially smaller width and cross section. Obviously, according to the invention, any other number of motor jacket passages 52 can be applied to the motor jacket 51.

[0134] At both ends 57 and 58 of the central motor housing body 51, the outer wall 54 is provided externally with a number of protrusions 59, each provided with a hole 60, possibly a threaded hole 60 or a through hole 60 without a thread. In the case shown, at each of the ends 57 and 58 there are six such protrusions 59, spaced from one another in a symmetrical manner around the circumference of the cylindrical element 53.

[0135] Furthermore, the central motor housing body 51 is closed at each side 58 and 59 with motor housing covers 61 and 62 (see FIG. 13). Specifically, the motor housing 3 comprises, at the drive side 8 of the central motor housing body 51, a drive side motor housing cover 61 adjacent the compressor rotors 11 and 12 driven by the motor 2, and, at the non-drive side 31 of the central motor housing body 51, a non-drive side motor housing cover 62 on the opposite side of the central motor housing body 51.

[0136] These covers 61 and 62 are provided with holes 63 and bolts 64 corresponding to the projections 59 and (threaded) holes 60 for bolting the covers 61 and 62 against the central motor housing body 51 .

[0137] Oil pump 32 has an oil pump inlet 65 and an oil pump outlet 66. Oil pump inlet 65 is connected to oil reservoir 47 by oil suction piping 67.

[0138] According to the invention, the motor jacket 51 comprises at least a first group 117 of motor jacket passages 52 consisting of one or more such motor jacket passages 52. The first group 117 of motor jacket passages 52 is intended to cool the motor 2. The first group 117 of motor jacket passages 52 intended to cool can consist of all the motor jacket passages 52, only a part of the motor jacket passages 52 or even just one motor jacket passage 52.

[0139] Another very general aspect of the invention is that the compressor assembly housing 27 includes one or more through passages for directing oil 49 through the compressor assembly housing 27. Further in accordance with the invention, such through passages form at least a portion of the aforementioned oil piping interconnecting the components of the compressor assembly 1.

[0140] In essence, this means that, according to the present invention, at least motor cooling is at least partially provided by a first group 117 of motor jacket passages 52 integrated into the motor jacket 51, and at least one oil line is at least partially integrated into the compressor assembly housing 27.

[0141] In the example of Figure 3, the compressor assembly housing 27, and more particularly the part of the compressor assembly housing 27 formed by the motor housing 3, is provided with such a through passage 68. The through passage 68 passes in this example through the central motor housing body 51 and through the motor housing covers 61 and 62 provided at the opposite ends 57 and 58 of the central motor housing body 51. For that purpose the covers 61 and 62 are also provided with through openings 69 and 70 which fit into the passages 71 of the aforementioned axially oriented passage 52 of the central motor housing body 51 so as to form together the through passage 68.

[0142] This is a practical example of a more general aspect of the invention, in that in a preferred embodiment of the compressor assembly 1 according to the invention, the motor jacket 51 comprises a second group of motor jacket passages 52 which are not of the first group 117 of motor jacket passages and therefore are not intended for motor cooling, but consist of one or more such motor jacket passages 52 each forming a through passage or part of such a through passage for guiding oil 49 through the motor jacket 51.

[0143] In this case, the oil pump 32 is connected at its outlet 66 directly to the through passage 68 to form a part 72 of an oil pump pressure line 73 of the oil pump 32 which is connected to the oil cooler 48. See also Figures 9 and 10, where a passage 71 for the through passage 68 is indicated and where the flow of oil 49 through the oil pump pressure line 73 coming from the oil pump 32 is indicated by the arrow PL.

[0144] The remaining part 74 of this oil pump pressure line 73 running between the motor housing 3 and the oil cooler 48 is formed by an oil line 74 which is connected to the outlet 75 of the through passage 68 at the drive side 8 of the motor housing 3. At its other end, this oil line 74 is connected to the inlet 76 of the oil cooler 48.

[0145] The integration in the motor jacket 51 of the part 72 of the oil pump pressure piping 73 to the oil cooler 48 has great advantages as far as compactness and robustness of the arrangement of the compressor assembly 1 are concerned. The risk of oil leakage at the oil pump outlet 66 is also very greatly reduced in this arrangement.

[0146] In this example, the oil pump pressure piping 73 is only partially integrated into the compressor assembly housing 27, but it will be apparent that in other possible embodiments the oil cooler 48 can be mounted on a housing part of the compressor assembly housing 27 and the oil pump pressure piping 73 can be fully integrated into the compressor assembly housing 27, for example by partially using the second group of motor jacket passages 52 in combination with passages provided in other parts of the compressor assembly housing 27.

[0147] 3, there is only one oil line going from the oil reservoir 47 to the oil pump 32, through the motor jacket 51 to the oil cooler 48, which consists of the suction line 67 and the oil pump pressure line 73. This means that the entirety of the oil 49 sucked by the oil pump 32 through the suction line 67 is transferred to the oil cooler 48, and therefore all the oil 49 circulated by the oil circulation system 33 of the compressor assembly design 1 is cooled before being supplied to the various components of the compressor assembly 1 where it is cooled and / or circulated.

[0148] Another aspect of the compressor assembly 1 of the present invention shown in Figure 3 is that the oil circulation system 33 of the compressor assembly 1 comprises at least one first circulation loop 77 and at least one second circulation loop 78, in which the oil 49 circulates between the oil reservoir 47 and the oil cooler 48 and back. The first circulation loop 77 is a non-filtered circulation loop 77 in which no oil filter 50 is included. On the other hand, the second circulation loop 78 is a filtered circulation loop 78 in which the oil filter 50 is provided to filter the oil 49.

[0149] The provision of more than one non-filtered circulation loop 77 and / or more than one filtered circulation loop 78 is not excluded from the invention.

[0150] In the compressor assembly 1 according to the invention, one or more motor jacket passages 79 are included in the first unfiltered circulation loop 77, or in one of the unfiltered circulation loops 77 if there is more than one. These motor jacket passages 79 form a first group 117 of motor jacket passages 79 forming a motor cooling passage 79 for cooling the motor housing jacket 51 and a motor cooling passage 79 for transferring heat generated in the motor 2 to the oil 49 flowing through the motor cooling passage 79 and removing this heat in order to cool the motor 2 itself.

[0151] As can be gathered from Figure 13 and shown diagrammatically with arrows in Figures 9 to 12, the motor housing covers 61 and 62 comprise one or more interconnecting passages 80 which, in the assembled state, cooperate with the axially oriented cooling passages 79 in the central motor housing body 51 to interconnect associated cooling passages 79 in the central motor housing body 51 and to form a single configured cooling passage 81 for cooling the motor housing jacket 51 and the motor 2. This single configured cooling passage is indicated by the arrow CC in Figures 9 to 12.

[0152] 9 to 12 show a compressor assembly 1 with a single configured cooling passage 81. However, in other embodiments of the compressor assembly 1 according to the invention it is of course also possible to provide two or more configured cooling passages 81, or to provide an unconfigured singular passage, in this case all cooling passages 52 being parallel to each other.

[0153] For example, a motor cooling setup can be designed in which a first configured cooling passage 81 circulates clockwise and a second configured cooling passage 81 circulates counterclockwise. Such a design is obviously somewhat more complex, but has the advantage of halving the flow rate through the configured cooling passage 81. As a result, the pressure drop across the configured cooling passage 81 is also reduced by a factor that is approximately four! This may be of particular interest for larger sized motors 2, where a large pressure drop across the configured cooling passage 81 may result in excessively high pressure in the cooling circuit.

[0154] To supply cooled oil 49 to the motor jacket 51, oil piping 82 is provided between an oil cooler outlet 83 of the oil cooler 48 and a cooling passage inlet 84 of at least one cooling passage 79 of the first group 117 in the central motor housing body jacket 51 or the configured cooling passages 81.

[0155] In more general terms, according to the present invention, it is preferred that the compressor assembly 1 comprises one or more oil cooling piping sections 115 extending from the oil cooler 48 to the oil reservoir 47, and that the first group 117 of motor jacket passages 79 are each included in one of the one or more oil cooling piping sections according to the present invention for cooling the motor 2.

[0156] In the case of FIG. 3, such an oil cooling piping section 115 comprises an oil piping 82 between the oil cooler 48 and the motor jacket 51, a cooling passage 81 consisting of a first group 117 of a plurality of motor jacket passages 79 interconnected using interconnecting passages 80, and a discharge passage 105.

[0157] An oil line 85 for cooled oil 49 branched upstream of the oil filter 50 into a first branch 86 forming an oil line 86 towards the oil filter 50 and a second branch 87 for forming an oil line 82 towards the cooling passage 79 or a single constituted cooling passage 81 in the motor housing jacket 51 is connected to an oil cooler outlet 83.

[0158] 3, the oil circulation system 33 of the compressor assembly 1 includes a number of oil injection lines for providing cooled, filtered lubricating oil 49 to the components of the compressor assembly 1 connected to the filter outlet side 88 of the filter 50. The oil filter 50 itself is provided in an oil line 86 for cooled oil 49 that extends between the oil cooler outlet 83 and the filter inlet side 89. In the case of FIG. 3, the oil 49 is cooled before being injected, so the oil circulation system 33 can be considered as a pre-cooled oil injection system.

[0159] Specifically, the oil circulation system 33 includes the following oil injection lines 90-99 for providing filtered lubricating oil to the components of the compressor element 9 of the compressor assembly 1: - filtered oil injection lines 90 towards the compressor rotors 11 and / or 12, - filtered oil injection lines 91 and 92 towards the driven gear 36 or the driving gear 37 of the intermediate gear transmission 34 between the motor 2 and the compressor element 9, - a non-drive oil injection line 93 for injecting the filtered oil 49 towards the compressor outlet 16; - drive side oil injection line 94 for injecting filtered oil 49 towards the compressor outlet 16; - filtered oil injection line 95 towards the non-drive bearing 21 of the female compressor rotor shaft 17; - filtered oil injection line 96 to the non-drive bearing 23 of the male compressor rotor shaft 18; - filtered oil injection line 97 towards the drive bearing 24 of the male compressor rotor shaft 18; - a filtered oil injection line 98 towards the drive side bearing 22 of the female compressor rotor shaft 17, and - Filtered oil injection line 99 to timing gear 28 or 29 will be provided.

[0160] In embodiments where the compressor element 9 is an oil-free or oil-free compressor element 9, there is of course no filtered oil injection piping 90. Also, other embodiments may employ more or less oil piping than in the examples disclosed herein.

[0161] The oil circulation system 33 is also provided with oil injection lines 100 and 101 for providing filtered lubricating oil to the components of the motor 2 of the compressor assembly 1. Specifically, the motor 2 in the case of FIG. - a drive side filtered oil injection line 100 towards the motor shaft bearing 45, and - Non-drive filtered oil injection pipe 101 to motor shaft bearing 46 will be established.

[0162] 8 shows how these oil injection lines 100 and 101 are realised to supply filtered and cooled oil 49 towards the motor bearings 45 and 46. For each bearing 45 and 46 supporting the motor shaft 4, an oil injection passage 102 is provided through the motor housing 3 to supply filtered oil to the associated motor shaft bearing 45 or 46.

[0163] In a possible embodiment, these oil injection passages 102 extend through one of the covers 61 or 62 of the motor jacket 51, or through the motor jacket 51 itself.

[0164] In a similar manner, there is also an oil drain passage 103 for draining filtered lubricating oil 49 from the associated motor shaft bearing 45 or 46 out of the motor housing and back to the oil reservoir 47 .

[0165] These oil injection passages 102 and oil discharge passages 103 extend in a radial direction RR' or SS' towards or away from the motor shaft 4 or at least comprise parts which extend in such a radial direction RR' or SS'.

[0166] In a preferred embodiment of the compressor assembly 1 according to the invention, the motor housing 3 is provided with an axially extending through passage 104 which is in principle similar to the through passage 68 for the oil pump pressure line 73 and which passes through the central motor housing body 51 and through openings in the motor housing covers 61 and 62 provided at the opposite ends 57 and 58 of the central motor housing body 51.

[0167] This axially extending through passage 104 is a drain passage 104 and forms part of an oil drain pipe 105 for draining the oil 49 coming from the motor shaft bearings 45 and 46 towards the oil reservoir 47. The axially extending through passage 104 is connected to the aforementioned radially extending part 103 for forming the oil drain pipe 105. The flow of the drained oil 49 is indicated by the arrows DC in Figures 9 to 12.

[0168] In more general terms, in accordance with the present invention, at least one such through passage 68 or 104, and preferably two or more such through passages 68 and 104, are provided in the compressor assembly housing 27 for directing oil 49 through the compressor assembly housing 27. While in the embodiment of FIG. 3 the through passages 68 and 104 extend primarily through only the motor housing 3, in other embodiments such through passages 68 and 104 may also extend through other parts of the compressor assembly housing 27.

[0169] Furthermore, according to the invention, such through passages 68 or 104 form at least a part of the oil piping interconnecting the components of the compressor assembly 1. It is not excluded from the invention that such through passages 68 or 104 are not only part of the aforementioned oil piping themselves, but also form, as a whole, such oil piping between the components of the compressor assembly 1.

[0170] For example, through passage 68 forms part 72 of oil pressure piping 73 between oil pump 32 and oil cooler 48, and through passage 104 forms part of oil discharge piping 105 for discharge oil 49 coming from motor shaft bearings 45 and 46 towards oil reservoir 47.

[0171] In other embodiments of the compressor assembly 1 according to the present invention, the oil injection passages 102 can also be implemented in a similar manner to the axially extending through passages 104, by integrating these oil injection passages 102 into the motor jacket 51 in axially extending passages 52 thereof.

[0172] Furthermore, the through-drain passage 104 is located at the bottom of the motor jacket 51 to receive the lubricating oil 49 under the influence of gravity, for example in a configuration where the motor 2 is typically oriented horizontally. In other configurations, the motor 2 extends vertically, which is the case for example in screw compressor elements 9 where oil is typically injected, and in such cases the lubricating oil 49 flows under the pressure of other forces, such as the driving force typically generated by an oil pump. The through-drain passage 104 is substantially smaller in cross-sectional size than the oil pump pressure piping 73 and the other passages 71 and 79 for cooling the motor jacket 51.

[0173] Of course, the oil 49 supplied to the compressor components through the oil inlet lines 90-99 also needs to be discharged back to the oil reservoir 47. To that end, the oil circulation system 33 of the compressor assembly 1 of FIG. 3 includes the following oil discharge lines: - an oil discharge pipe 106 for discharging the oil coming from the compressor rotor 11 or 12; - oil discharge pipes 107 and 108 coming from the driven gear 36 or the driving gear 37 of the intermediate gear transmission 34 between the motor 2 and the compressor element 9, - an oil drain pipe 109 for draining the oil 49 coming from the non-drive bearing 21 of the female compressor rotor shaft 17, - an oil drain pipe 110 for draining oil coming from the non-drive bearing 23 of the male compressor rotor shaft 18; - an oil drain pipe 111 for draining the oil 49 coming from the drive-side bearing 22 of the female compressor rotor shaft 17, - an oil drain pipe 112 for draining the oil 49 coming from the drive side bearing 24 of the male compressor element rotor 18, - an oil drain pipe 113 for draining the oil 49 coming from the timing gear 28 or 29, and an oil drain pipe 114 for draining the oil 49 coming from the passages 79 of the first group 117 in the motor jacket 51 Equipped with.

[0174] All these oil discharge lines 106 - 113 together direct the oil 49 back to the oil reservoir 47 to be sucked again by the oil pump 32 for the next cycle through the oil circulation system 33 .

[0175] According to the present invention, all these oil discharge pipes 106-114 or one or more of the oil injection pipes 90-101 may be fully or partially integrated into the compressor assembly housing 27, for example by means of through passages provided in the motor jacket 51 and / or in other parts of the compressor assembly housing 27.

[0176] FIG. 4 shows another embodiment of a compressor assembly 1 according to the invention in a similar manner as in FIG.

[0177] Most of the constituent elements are the same as in Figure 3 and are also designated with the same reference numerals. The main difference with respect to the embodiment of Figure 3 is that in the embodiment of Figure 4, the oil 49 supplied to the elements of the compressor element 9 and the bearings 45 and 46 of the motor 2 for lubrication is not pre-cooled as is the case in the embodiment of Figure 3.

[0178] In the example of Fig. 4, the oil circulation system 33 of the compressor assembly 1 includes oil injection pipes 90-101 for supplying uncooled filtered lubricating oil 49 to the components of the compressor assembly 1. In this case, the oil filter 50 is provided in an oil pipe 116 for uncooled oil 49 branched off from an oil pump pressure pipe 73 provided between the oil pump 32 and the oil cooler 48. This oil pump pressure pipe 73 also partially passes through the motor jacket 51 through the through passage 68.

[0179] Therefore, the main difference is that in the embodiment of Figure 3 the oil filter 50 is located in the oil line branch 86 downstream or after the oil cooler 48, whereas in the embodiment of Figure 4 the oil filter 50 is located in the oil line branch 116 upstream or before the oil cooler 48. Besides the fact that the oil 49 is not cooled before being supplied to the relevant components for lubrication, there are no other essential differences between both compressor assemblies 1.

[0180] 5 to 7 show successive steps during the manufacture of a central motor housing body 51 of an electric motor according to the method of the invention.

[0181] In accordance with the present invention, the manufacture of the central motor housing body 51 of the compressor assembly 1 includes an extrusion step to form the motor jacket 51 with axially oriented passages 52 .

[0182] 5 shows the still unfinished state immediately after the extrusion step has been carried out. The central motor housing body 51 already has all the important features present in the finished central motor housing body 51, such as the shape of a cylindrical double-walled element 53 with an essentially constant or unchanging cross section at least over a significant axial portion of the central motor housing body 51, between an inner wall 55 and an outer wall 54, separated by a partition 56, in which an axially oriented passage 52 is provided. The projections 59 provided externally on the outer wall 54 are still not completed, but are axially aligned projections extending over the entire length of the central motor housing body 51.

[0183] 6 shows the result after the execution of the next step of the method of the invention, whereby a middle part of the projection 59 has been removed by a milling or cutting operation. A hole 60, possibly provided with an internal thread, or simply executed as a through hole 60 without an internal thread, is further provided in the projection 59.

[0184] Finally, FIG. 7 shows the central motor housing body 51 after the motor stator 6 has been inserted into the double walled cylindrical element 53.

[0185] 11 and 12 show part of an arrangement of an oil circulation system 33 according to the present invention which differs slightly from the arrangement depicted in FIGS.

[0186] The difference is that in the embodiment of Figures 11 and 12 there is one less passage 52 in the central motor housing body 51 than is the case in the embodiment of Figures 9 and 10. The motor jacket passage 71 forming part 72 of the oil pump pressure line 73 has been omitted in the embodiment of Figures 9 and 10. As a result, the oil pump pressure line 73 is now not integrated into the motor jacket 51 and in this example both the oil pump suction line 67 and the oil pump pressure line 73 must be connected externally to the oil pump 32.

[0187] Likewise, it is not excluded from the invention to omit the drain passage 104 integrated into the motor jacket 51 at its bottom and, for example, to drain the oil 49 coming directly from the motor bearings 45 and 46 into the underlying oil sump by guiding the oil 49 through one or more through passages provided in other parts of the compressor assembly housing 27.

[0188] Of course, other configurations are not excluded from the invention, for example, the axially aligned passages 52 in the motor jacket could have completely different shapes or sizes, the number of passages 52 provided could be increased or decreased, etc.

[0189] Not integrating the oil pump pressure pipe 73, the oil injection pipe 102 and / or the oil discharge pipe 104 (or any other non-cooled passages) into the motor jacket 51 has the advantage that the cooling performance of the motor 2 can be increased. On the other hand, integrating more oil pipes into the motor jacket 51 is advantageous in that the motor 2 can be executed in a more compact form. Possible interesting candidates that can be additionally integrated into the motor jacket 51 in order to increase the compactness of the assembly 1 and to reduce the risk for oil leakage are, for example, the oil pump suction pipe 67 or any oil injection pipes 90-101. However, a drawback of increasing the integration of oil pipes in the motor jacket 51 is that the cooling output of the motor 2 is then somewhat reduced.

[0190] The remaining Figures 14 to 31 show different configurations of the compressor assembly 1 according to the present invention, possibly applying particular degrees of integration of different components and oil piping in the compressor assembly housing 27.

[0191] However, the first part of the integration of components in the compressor assembly housing 27 that is present in all depicted configurations is that the motor jacket 51 comprises at least a first group 117 of motor jacket passages 79 consisting of one or more such motor jacket passages 52 that are intended to cool the motor 2. In the example of Figures 14-31, this first group 117 of motor jacket passages 79 are combined into a single configured cooling passage 81 by means of interconnecting passages 80 provided in covers or caps 61 and 62 mounted on opposite sides 57 and 58 of the central motor housing body 51, as was the case in the previous examples. However, this is not necessarily the case according to the present invention.

[0192] The schematic diagram of Fig. 14 depicts in a simplified manner the main components of a compressor assembly 1 that is similar to the embodiment depicted in Fig. 3. Besides the first group 117 of motor jacket passages 79, in this Fig. 14 no other through passages of the compressor assembly 1 are depicted as being integrated into the compressor assembly housing 27. According to the invention, one or more of the oil lines 90-101 or 106-114 depicted in the figure may be integrated into a part of the compressor assembly housing 27 that is not part of the motor housing 3, for example.

[0193] 14 and 15 , the motor jacket passages 52 are all of the first group 117, which together form a cooling passage 81 configured to serve to cool the motor 2. The passages 52 of the motor jacket 51 are not intended for any purpose other than cooling the motor 2.

[0194] Figures 16 and 17 show another embodiment of a compressor assembly 1 according to the invention, in which an oil drain pipe 105 for draining the oil 49 coming from the motor shaft bearing 7 to the oil reservoir 47 is partially or totally integrated into the motor housing 3, as was the case in the already existing embodiments of figures 3 and 4.

[0195] The integration comprises not only axially extending through passages 104 formed by axially extending motor jacket passages 104 for guiding the oil 49 through the motor jacket 51, but also radially extending through passages 103 provided in the compressor assembly housing 27 or in the motor housing 3 for discharging the oil 49 from the motor shaft bearing 7 towards the motor jacket 51. The motor jacket passages 104 concerned are not the motor jacket passages 52 of the first group 117, since these motor jacket passages 52 of the first group 117 are intended to cool the motor 2.

[0196] In the embodiment of Figures 16 and 17, the motor jacket 51 comprises a second group 118 of motor jacket passages 52 consisting of only one such motor jacket passage 104, which in this case is intended to drain oil 49 from the motor shaft bearing 7 to the oil reservoir 47.

[0197] Figures 18 and 19 show yet another embodiment of the compressor assembly 1 according to the invention and its central motor housing body 51, in this example applying yet a further form of integration. Indeed, in the illustrated example of Figures 18 and 19, the non-drive filtered oil injection line 101 for guiding the oil 49 towards the motor shaft bearing 7 is at least partially integrated in the motor jacket 51 by means of an axially extending motor jacket passage 119. Also integrated in the motor housing 3 is a radially extending oil injection passage 102 which runs through one of the covers 61 or 62 of the motor jacket 51 or through the motor jacket 51 itself.

[0198] In this case, the motor jacket 51 not only comprises a first group 117 of motor jacket passages 79 for cooling the motor 2, but also explicitly comprises a second group 118 of motor jacket passages 52 consisting of motor jacket passages 119 for injecting oil 49 towards the motor shaft bearing 7 and motor jacket passages 104 for draining oil 49 from the motor shaft bearing 7 towards the oil reservoir 47.

[0199] The motor jacket passages 104 and 119 are not of the first group 117 of motor jacket passages 79 because they are not intended to cool the motor 2 and each forms a through passage or part of such a through passage for guiding oil 49 through the motor jacket 51.

[0200] Naturally, additionally, an oil injection line 100 for guiding oil 49 towards the drive-side motor shaft bearing 45 can be integrated into the motor jacket 51 by means of a part of the motor jacket passage 119 in combination with a radially extending oil injection passage 102 provided in the motor housing 3. Similarly, in case at least a drive-side motor shaft bearing 45 is present, an oil drainage line 105 can be integrated into the motor housing jacket 51 and / or the compressor assembly housing 27 at the drive side 8 of the motor housing 3, possibly in combination with a part of the motor jacket passage 104, in order to drain the oil 49 from such bearing 45 by means of a radially extending passage 103 integrated into the motor housing 3.

[0201] In Fig. 19, the motor jacket passages 104 and 119 of the second group 118 for lubricating the motor shaft bearings 7 are positioned on opposite sides of the central motor housing body 51, but this is not necessarily the case. This configuration is useful, for example, when the first group 117 of motor jacket passages 117 is split into two portions (a left portion and a right portion in Fig. 19) that are interconnected to respectively form the configured cooling passages 81. In other embodiments, the motor jacket passages 104 and 119 may be positioned near each other, for example.

[0202] Figures 20 and 21 show another embodiment of the compressor assembly 1 and its central motor housing body 51, in which an even more detailed form of integration is applied.

[0203] In the previous examples, the compressor assembly housing 27 comprises the motor housing 3, the compressor housing 10 and the intermediate housing compartment 26, each for accommodating integrated compressor assembly components 120 in the compressor assembly housing 27, which in each of these examples are the motor 2, the compressor element 9 and the interconnection means 25 or 34 for interconnecting the motor 2 and the compressor element 9.

[0204] In the embodiments of Figures 16, 18, 20, and still other figures, the oil reservoir 47 is fixedly mounted beneath the aforementioned portions of the compressor assembly housing 27 and therefore can be considered to be an integral part of the compressor assembly housing 27 or integrated compressor assembly component 120.

[0205] Furthermore, in all considered examples the oil pump 32 also forms an integrated compressor assembly component 120 since it is mounted to the motor housing 3 or to a housing part which is mounted to the motor housing 3 and the oil pump 32 is driven by the motor shaft 4.

[0206] 20, the compressor assembly housing 27 additionally comprises an oil filter housing 121 fixedly mounted in the mid-housing compartment 26. The oil filter 50 is mounted in the oil filter housing 121, forming yet another integrated compressor assembly component 120.

[0207] In yet other embodiments not depicted in the figures, the oil cooler 48, or other components of the compressor assembly 1, may form an integrated compressor assembly component 120 that is housed in the compressor assembly housing 27 or in a housing part mounted to the compressor assembly housing 27.

[0208] Another feature of the embodiment shown in Figures 20 and 21 is that, in addition, compared to the example of Figure 18, the oil pump pressure piping 73 is partially integrated into the motor jacket 51 by means of the motor jacket passages 71 of the second group 118, as was the case in the example of Figures 3 and 4.

[0209] Thus, the embodiment of Figures 20 and 21 has a very high degree of integration in that the oil inlet piping 101 for injecting oil 49 into the motor shaft bearing 7 and the oil outlet piping 105 for draining oil 49 from the motor shaft bearing 7 are partially integrated into the oil pump pressure piping 73 as well as the motor jacket 51.

[0210] Furthermore, in the embodiment depicted in Figures 20 and 21, the generally preferred principle of the present invention also applies, that an integrated compressor assembly component 120, or an integrated element 122 of such an integrated compressor assembly component 120 that needs to be lubricated or cooled, is preferably connected to other such integrated compressor assembly components 120, or other such integrated elements, by means of oil piping formed generally by through passages provided in the compressor assembly housing 27 to form an overall integrated oil piping.

[0211] 20 embodiment, oil piping 101 interconnects, for example, oil filter 50, which is an integrated compressor assembly component 120, and motor shaft bearing 7, which is an integrated element 122 of motor 2 which itself forms integrated compressor assembly component 120. Integrated element 122 of motor 2 needs to be lubricated by oil 49, and oil piping 101 for supplying this oil 49 is totally integrated in compressor assembly housing 27.

[0212] In fact, the oil line 101 concerned is entirely formed by through passages 123 provided in the compressor assembly housing 27 to form an entirely integrated oil line 123. The oil line 101 is provided in the compressor assembly housing 27 between the oil filter 50 and the motor jacket 51, i.e. it comprises through passages 124 provided in the oil filter housing 121, the intermediate housing compartment 26 and the motor housing, as well as a second group 118 of motor jacket passages 119 connected to other through passages 102 provided in the motor housing 3.

[0213] Similarly, one or more of the oil injection piping 90-99 each extending between the integrated oil filter 50 and an integrated element 122 of the compressor assembly 1 (specifically, of the compressor element 9 or the gear transmission device 34) that needs to be lubricated may be generally integrated into the compressor assembly housing 27 using one or more through passages 125 provided in the compressor assembly housing 27 to form a generally integrated oil piping 125.

[0214] In the embodiment of FIG. 20, the oil piping 82 or even the oil piping branch 87 between the oil cooler 48 and the motor jacket passages 79 of the first group 117 in the motor jacket 51 is partially integrated into the compressor assembly housing 27 by means of a through passage 126.

[0215] Of course, in a preferred embodiment of the compressor assembly 1 according to the present invention, each interconnecting oil piping between the integrated compressor assembly components 120 and / or their integrated elements 122 is formed by the aforementioned generally integrated oil piping 123 or 126, thereby obtaining maximum integration of the oil piping in the compressor housing 27.

[0216] 21 further shows that the motor jacket passage 71 for the oil pump pressure line 73 is located between the motor jacket passages 104 and 119 for lubrication of the motor shaft bearing 7. In this case there are three motor jacket passages 73, 104, and 109 in a second group 118.

[0217] Specifically, the cross-sectional size of the motor jacket passage 71 for the oil pump pressure line 73 is much larger than the cross-sectional size of the motor jacket passages 104 and 119. This is apparent because the oil pump pressure line 73 provides oil 49 to all of the oil lines in the oil circulation system 33.

[0218] The cross-sectional size of the motor jacket passage 71 for the oil pump pressure piping 73 is approximately the same as the cross-sectional size of the motor jacket passages 79 of the first group 117 for cooling the motor 2, since motor cooling requires the largest portion of the oil flow through the oil circulation system 33.

[0219] The embodiment shown in Figures 22 and 23 is similar to the embodiment depicted in Figures 18 and 19. The only difference is that in the embodiment of Figures 22 and 23, the oil pump suction pipe 67 is now embedded in the compressor assembly housing 27. In fact, a through passage 127 integrated in the compressor assembly housing 27 between the oil reservoir 47 and the oil pump inlet 65 forms the oil pump suction pipe 67, which is therefore also the entirely integrated oil pipe 128.

[0220] In the embodiment of the compressor assembly 1 according to the invention shown in Figures 24 and 25, the second group 118 of motor jacket passages 104 present in the previous example, intended to drain oil 49 from the motor shaft bearings 7 towards the oil reservoir 47, has been eliminated.

[0221] Instead, the oil drain passage 103 is extended and integrated into the compressor assembly housing 27 between the motor shaft bearing 7 and the oil reservoir 47 to form a through passage 129 which forms an overall integrated oil piping 129 between an integrated element 122 of the motor 2 (represented by the motor shaft bearing 7) and an integrated component 120 of the compressor assembly 1 (represented by the oil reservoir 47).

[0222] The oil pump pressure piping 73 is again partially integrated into the compressor assembly housing 27 by means of a through passage 68 including the motor jacket passages 71 of the second group 118, as was the case in the embodiment of FIG. 20, for example.

[0223] 20, the oil piping 90-101 between the oil filter 50 and the compressor assembly 1 is mounted at least partially outside the compressor assembly housing 27. The connection to the oil cooler 48 is also made by means of oil piping that is at least partially outside the compressor housing 27.

[0224] Thus, while the depicted embodiment of FIG. 24 has a somewhat more sophisticated form of integration insofar as the portion of the oil circulation system 33 associated with the oil pump 32 is concerned, it has a somewhat less sophisticated form of integration insofar as the connections between the oil filter 50 and the oil cooler 48 are concerned.

[0225] FIG. 25 shows that in a relevant embodiment of the compressor assembly 1 according to the invention, the motor jacket 51 comprises only two motor jacket passages 71 and 101 of a second group 118, respectively for injecting oil 49 into the motor shaft bearings 7 and for partially integrating the oil pump pressure piping 73 in the motor housing 3.

[0226] Non-drive side filtered oil injection pipe 101 toward motor shaft bearing 46

[0227] The embodiment of the compressor assembly 1 shown in Figure 26 is a kind of combination of the embodiments depicted in Figures 20 and 22. In fact, a totally integrated oil line 128 between the oil shaft bearing 7 and the oil reservoir 47 is formed by a through passage 127 provided in the compressor assembly housing 27, constituting the oil pump suction line 67.

[0228] However, the second group 118 of motor jacket passages 104, omitted in the embodiment of Figure 24, is maintained in the embodiment of Figure 26. These motor jacket passages 104 still form part of the oil drainage pipe 105 between the motor 2 and the oil reservoir 47 and are intended to drain any leaking oil 49 from the motor 2 towards the oil reservoir 47.

[0229] The oil pump pressure piping 73 is again partly formed by the motor jacket passages 71 of the second group 118, and in total the motor jacket 51 again comprises three motor jacket passages 71, 104 and 101 of the second group 118 which are not intended for cooling the motor 2.

[0230] The example shown in Figures 28 and 29 introduces a higher degree of integration of compressor assembly 1 components 120 and oil piping in the same compressor assembly housing 27 compared to the previous embodiment of Figure 26.

[0231] Here, the oil filter 50 and the associated oil pipes 90-101 or one or more of these oil pipes 90-101 connected to the oil filter 50 are again integrated into the compressor assembly housing 27, as was the case in the embodiment of Figure 20.

[0232] Finally, the embodiment depicted in Figures 30 and 31 is a simplification of the previous embodiment of Figures 28 and 29, since the only difference is that the motor jacket passage 104 for draining leaking oil from the motor 2 to the oil reservoir 47 has been eliminated. The remaining parts are identical, with the result that the motor jacket 51 has only two motor jacket passages 71 and 101 of the first group, respectively for forming part of the oil pump pressure pipe 73 and for forming the oil injection pipe 101 towards the motor shaft bearing 7, apart from the motor jacket passages 79 of the first group 117 for motor cooling.

[0233] It will be apparent that many other configurations involving more or less integration of the oil piping and other components of the compressor assembly 1 in the same compressor assembly housing 27 are applicable.

[0234] The present invention is not limited to the embodiment of the compressor assembly 1 as described above, and such compressor assembly 1 can be applied and implemented in many different ways without departing from the scope of the present invention. [Explanation of symbols]

[0235] 1 Compressor assembly, compressor assembly design 2 Electric motor 3 Motor housing 4 Motor shaft, rotor shaft 5 Motor rotor 6 Motor stator windings 7 Motor shaft bearings, oil shaft bearings 8 Drive side 9 Compressor elements 10 Compressor housing 11, 12 Compressor rotor 13 Fluid 14 Compressor inlet 15 Compressed or pressurized fluids 16 Compressor outlet 17 Female Compressor Rotor Shaft 18 Male compressor rotor shaft, male compressor element rotor 19 Compressor rotor, female rotor, compressor teeth 20 Compressor rotor, male rotor, compressor teeth 21, 23 Compressor shaft bearing, non-drive side bearing 22, 24 Compressor shaft bearing, drive side bearing 25 Direct Coupling, Interconnection Means 26 Intermediate housing compartment 27 Compressor assembly housing 28, 29 Timing gear 30 Non-drive end 31 Non-drive side 32 Oil Pump 33 Oil Circulation System 34 Intermediate gear transmission device, interconnection means 35 Intermediate gear transmission housing 36 Driven gear, driven pinion gear 37 Driving gear, bull gear 38 Free end of compressor rotor shaft 18 39 Additional gear transmission shaft 40, 41 Bearings 42 Free end of additional gear transmission shaft 39 43 Free end of motor shaft 4 44 Free end of additional gear transmission shaft 39 45, 46 Motor shaft bearing 47 Oil Reservoir 48 Oil cooler 49 Oil 50 Oil Filter 51 central motor housing body, motor housing jacket 52 Motor jacket passage 53 Double-walled elements, cylindrical elements 54 Exterior Wall 55 Inner wall 56 Bulkhead 57, 58 distal, lateral 59 Protrusion 60 Female threaded hole, through hole without female thread 61 Drive side motor housing cover 62 Non-drive side motor housing cover 63 holes 64 Volts 65 Oil pump inlet 66 Oil pump outlet 67 Oil suction pipe, oil pump suction pipe 68 Passageway 69, 70 Through hole 71 Passage, motor jacket passage 72 Part of oil pump pressure piping 73 73 Oil pump pressure piping 74 Remaining part of oil pump pressure piping 73, oil piping 75 Exit of Passage 68 76 Inlet of oil cooler 48 77 First circulation loop, non-filtered circulation loop 78 Second circulation loop, filtration circulation loop 79 Motor jacket passage, motor cooling passage 80 Interconnecting Passages 81 configured cooling passage, first configured cooling passage, second configured cooling passage 82 Oil piping 83 Oil cooler outlet 84 Cooling passage entrance 85 Oil piping 86 Oil pipe, first branch, oil pipe branch 87 Second branch, oil pipe branch 88 Filter outlet side 89 Filter inlet side 90 Filtered oil injection pipe 91, 92 Filtered oil injection piping 93 Non-drive side oil injection piping 94 Drive side oil injection piping 95, 96, 97, 98, 99 Filtered oil injection piping 100 Drive side filtered oil injection piping 101 Non-drive side filtered oil injection piping, motor jacket passage 102 Oil injection passage, oil injection piping 103 Oil discharge passage, radially extending parts, through passage 104 Through-hole drain passage, oil drain pipe, motor jacket passage, through-hole 105, 106, 107, 108, 109, 110, 111, 112, 113, 114 Discharge passage, oil discharge piping 115 Oil cooling piping area 116 Oil piping for uncooled oil 49, oil piping branch 117 First group of motor jacket passages 52, first group of motor jacket passages 79 118 second group of motor jacket passages 52 119 Motor jacket passage 120 Integrated Compressor Assembly Components 121 Oil filter housing 122 Integrated Elements 123, 125, 126, 128, 129 Totally integrated oil piping, through passages 124 Through passage AA', BB', CC', DD', EE', FF', XX' Axial direction DC Discharged Oil 49 Flow PL Flow of oil 49 coming from oil pump 32 RR', SS' Radial direction

Claims

1. A compressor assembly (1) comprising a compressor assembly housing (27) and a motor (2) for driving one or more compressor rotors (11, 12) of a compressor element (9), the compressor assembly (1) further comprising an oil circulation system (33) for cooling and lubricating the components (2, 7, 9, 34, ...) of the compressor assembly (1), the oil circulation system (33) comprising an oil reservoir (47) and one or more oil pipes (9) of the oil circulation system (33) interconnecting the components of the compressor assembly (1). 0 to 101, 105 to 116, ...), and an oil cooler (48) and an oil filter (50) for respectively cooling and filtering the oil (49) flowing through said motor (2), said motor (2) having a motor housing (3) with a central motor housing body (51) implemented as a motor jacket (51) in which a motor jacket passage (52) is provided for circulating the oil (49) passing through said motor jacket (51), said motor jacket (51) comprising at least a first group (117) of motor jacket passages (52, 79) consisting of one or more such passages (52) intended to cool said motor (2); the compressor assembly housing (27) is provided with one or more through passages (67, 68, 123, 125, 126, 128, 129, ...) for guiding oil (49) through the compressor assembly housing (27), and such through passages (67, 68, 123, 125, 126, 128, 129, ...) form at least a part of the oil piping (90-101, 105-116, ...) interconnecting components (2, 7, 9, 34, ...) of the compressor assembly (1).

2. the compressor assembly housing (27) houses an integrated compressor assembly component (120) comprising at least the motor (2), the compressor element (9), and interconnection means for interconnecting the motor (25, 34) and the compressor element (9), and possibly one or more other integrated compressor assembly components (120), such as the oil reservoir (48), the oil filter (50), the oil cooler (48), an oil pump (32), and possibly still other integrated compressor assembly components (120); 2. Compressor assembly (1) according to claim 1, characterized in that an integrated compressor assembly component (120) or an integrated element (122) of such integrated compressor assembly component (120) which needs to be lubricated or cooled is connected to other such integrated compressor assembly components (120) or other such integrated elements (122) by means of said oil piping (90-101, 105-116, ...) which is generally formed by through passages (123, 125, 127, ...) provided in said compressor assembly housing (27) to form an overall integrated oil piping (123, 125, 128, 129, ...).

3. 3. A compressor assembly (1) according to claim 2, characterized in that the respective interconnecting oil piping (103, 123, 125, 127) between the integrated compressor assembly components (120) and / or its integrated elements (122) is formed by said generally integrated oil piping (123, 125, 128, 129).

4. the compressor assembly (1) comprising one or more oil cooling piping sections (115) extending from the oil cooler (48) to the oil reservoir (47); 4. The compressor assembly (1) according to claim 1, wherein the first group (117) of motor jacket passages (79) are each included in one of the one or more oil cooling piping sections (115) for cooling the motor (2).

5. the oil circulation system (33) of the compressor assembly (1) comprises at least a first circulation loop (77) and a second circulation loop (78) in which oil (49) circulates between the oil reservoir (47) and the oil cooler (48) and back; 5. The compressor assembly (1) according to claim 1, characterized in that the first circulation loop (77) is a non-filtered circulation loop (77) not including an oil filter (50) and the second circulation loop (78) is a filtered circulation loop (78) in which the oil filter (50) is provided for filtering the oil (49), and the motor jacket passages (52, 79) of the first group (117) are included in the first non-filtered circulation loop (77), the passages (52) forming a cooling passage (79) for cooling the motor housing jacket (51).

6. 6. A compressor assembly (1) according to any one of claims 1 to 5, characterized in that the motor jacket (51) comprises a second group (118) of motor jacket passages (52) consisting of the aforementioned through passages (68, 101, 104) or one or more such passages (52, 71, 101, 104) each forming part of such a through passage (68, 101, 104) for guiding oil (49) through the motor jacket (51), rather than the first group (117) of motor jacket passages (52, 79).

7. The following oil piping of the compressor assembly (1): - oil lines (67, 73, 85, 86) for supplying oil (49) from said oil reservoir (47) to said oil filter (50) and / or to said oil cooler (48); - oil lines (90-101) connected to the outlet (88) of the oil filter (50) for supplying filtered oil (49) to the components (7, 28, 29, 34, 40, 41, 45, 46, ...) of the compressor assembly (1); - oil lines (82, 85) connected to an outlet (83) of the oil cooler (48) for supplying cooled oil (49) to the components (2, ...) of the compressor assembly (1); - oil injection lines (90-101) for supplying oil (49) to the components (7, 28, 29, 34, 40, 41, 45, 46, ...) of said compressor assembly (1) for lubrication purposes, and / or - oil discharge pipes (105-116) for discharging oil (49) coming from the components (7, 28, 29, 34, 40, 41, 45, 46, ...) of said compressor assembly (1) towards said oil reservoir (47); 7. The compressor assembly (1) according to claim 6, characterized in that one or more of the first group (118) of motor jacket passages (52) are at least partially integrated in the motor jacket (51) by being partially formed by one or more motor jacket passages (52) of the second group (118).

8. the oil circulation system (33) comprising an oil pump (32) for providing a driving force for circulating oil (49) from the oil reservoir (47) through oil piping of the oil circulation system (33) to the associated components to be cooled and / or lubricated and back to the oil reservoir (47); The following oil piping of the compressor assembly (1): - an oil pump suction line (67) for connecting the oil reservoir (47) with an inlet (65) of the oil pump (32) of the compressor assembly (1); - an oil pump pressure line (73) for connecting the outlet (66) of the oil pump (32) with the oil cooler (47) and / or the oil filter (50); 8. The compressor assembly (1) according to claim 1, wherein one or more of the first and second motor jackets (51) of the second group are at least partially integrated in the motor jacket (51) by being partially formed by one or more motor jacket passages (52) of the motor jackets (51) of the second group, or are at least partially integrated in the compressor assembly housing (27).

9. 6. The compressor assembly (1) according to claim 5, characterized in that the oil pump (32) is integrated in the motor housing (3) or is mounted on a motor housing cover (62) or on another part of the compressor assembly housing (27) provided on the non-drive side (31) or on the drive side (8) of the central motor housing body (51) and is driven by the motor shaft (4) of the motor (2).

10. Compressor assembly (1) according to claim 5 or 6, characterized in that the oil pump (32) is connected at its outlet (66) directly to the aforementioned motor jacket passages (52, 71) of the second group provided in the central motor housing body (51).

11. The motor housing (3) is provided with a through passage (68) that passes through the central motor housing body (51) and through motor housing covers (61, 62) provided at the opposite ends (57, 58) of the central motor housing body (51); 11. A compressor assembly (1) according to any one of claims 1 to 10, characterized in that the outlet (66) of the oil pump (32) is directly connected to this through passage (68) and at least partially (72) forms an oil pump pressure line (73) of the oil pump (32).

12. the motor housing (3) additionally comprises a drive side motor housing cover (61) adjacent to the compressor rotor (11, 12) driven by the motor (2) on the drive side (8) of the central motor housing body (51) and a non-drive side motor housing cover (62) on the opposite side of the central motor housing body (51) on the non-drive side (31) of the central motor housing body (51); 12. The compressor assembly (1) according to any one of claims 1 to 11, characterized in that the motor housing cover (61, 62) comprises one or more interconnecting passages (80) cooperating in assembly with the first group (117) of motor jacket cooling passages (52, 79) to interconnect the associated cooling passages (52, 79) so as to form a single or multiple configured cooling passages (81) for cooling the motor housing jacket (51).

13. 13. The compressor assembly (1) according to claim 12, characterized in that the motor housing cover (61, 62) comprises one or more through openings (69, 70) cooperating in an assembled state with the motor jacket passages (71) of the second group (188) to form a through passage (68) through the motor housing (3).

14. The compressor assembly (1) according to any one of claims 1 to 13, characterized in that the passages (52) in the motor jacket (51) extend in an axial direction (AA', BB', CC', DD', EE', FF', ...) parallel to an axial direction (XX') of the motor shaft (4) of the motor (2).

15. The compressor assembly housing (27) has a compressor assembly housing main portion consisting of a motor housing (3) interconnected with the compressor housing (10) possibly by means of an intermediate housing (26) for coupling the motor shaft (4) to the compressor rotor shafts (17, 18) directly or indirectly by means of a gear transmission (34); The compressor assembly housing (27) is mounted directly to the main compressor assembly housing and comprises: - an oil pump housing for accommodating an oil pump (32) driven by said motor (2); - an oil filter housing (121) for accommodating said oil filter (50); - a sump or reservoir housing (47), and / or - an oil cooler housing for accommodating said oil cooler (48); 15. The compressor assembly (1) according to any one of claims 1 to 14, additionally comprising one or more additional compressor assembly housing parts (121) including one or more of:

16. the oil circulation system (33) of the compressor assembly (1) comprises one or more oil injection lines (90-101) for providing cooled and filtered lubricating oil (49) to the components (7, 28, 29, 34, 40, 41, 45, 46, ...) of the compressor assembly (1); the oil filter (50) is provided in an oil pipe (85, 86) for the cooled oil (49) that is connected to the oil cooler outlet (83); Compressor assembly (1) according to any one of the preceding claims, characterized in that one or more of the oil injection pipes (90-101) are at least partially integrated into the compressor assembly housing (27).

17. for the motor jacket cooling oil lines (85, 87) of cooled oil (49), an oil line (82) is provided between the oil cooler outlet (83) and at least one cooling passage (52, 79) in the central motor housing body jacket (51) or one or more configured cooling passages (81), the one or more configured cooling passages (81) consisting of several cooling passages (52, 79) in the central motor housing body jacket (51) interconnected by means of interconnecting passages (80) in the motor housing cover (61, 62) of the central motor housing body (51); an oil pipe (85) for cooled oil (49) is connected to the oil cooler outlet (83) which branches upstream of the oil filter (50) to a first branch (86) towards the oil filter (50) and a second branch (87) towards the cooling passages (52, 79) or one or more configured cooling passages (81) in the motor housing jacket (51); Compressor assembly (1) according to any one of the preceding claims, characterized in that the second branch (87) is at least partially integrated in the compressor assembly housing (27).

18. the oil circulation system (33) of the compressor assembly (1) comprises one or more oil injection lines (90-101) for providing uncooled, filtered lubricating oil (49) to the components (7, 28, 29, 34, 40, 41, 45, 46, ...) of the compressor assembly (1); the oil filter (50) is provided in an oil pipe (116) for uncooled oil (49) branched off from an oil pump pressure pipe (73) provided between the oil pump (32) and the oil cooler (48); Compressor assembly (1) according to any one of the preceding claims, characterized in that one or more of the oil injection lines (90-101) are at least partially integrated into the compressor assembly housing (27).

19. for each bearing (45, 46) supporting said motor shaft (4), an oil inlet passage (102) is provided for supplying filtered oil (49) to the associated motor shaft bearing (45, 46) as well as to an oil outlet passage (103) for draining the lubricating oil (49) from said associated motor shaft bearing (45, 46); Compressor assembly (1) according to any one of the preceding claims, characterized in that one or more of these oil injection passages (102) and / or oil discharge passages (103) are at least partially integrated into the compressor assembly housing (27).

Images